Apparatus for drill stem testing



May 26, 1964 A. BARRY ETAL APPARATUS FOR DRILL STEM TESTING 5Sheets-Sheer. 1

Original Filed May 9, 1960 F I G. I. FIG. IA FIG. 2.

SWABBING UNIT g LATCH szcnou SOLENOID SECTION PRESSURE SWITCH B8BATTERIES SWAB CUPS MAGNET i HI m. 4 7/11 I VII/I! FIG. 2A.

INVENTORS.

m RU A O BM T D R M B M L E W D H A W ATTORNEY.

May 26, 1964 A. BARRY ETAL APPARATUS FOR DRILL STEM TESTING 3Sheets-Sheet 2 Original Filed May 9, 1960 F'|G.4A. FIG.4B. FIG.4C. Fl

w w As w IN VEN TORJ ADELBERT BARRY,

BY WHlTMAN D. MOUNCE,

ATTORNE May 26, 1964 A. BARRY ETAL APPARATUS FOR DRILL STEM TESTING 3Sheets-Sheet 3 Ofiginal Filed May 9, 1960 FROM PACKER i I i If ESOVLENOID 12s INVENTORJ'. ADELBERT BARRY, BY WHITMAN D.MOUNCE,

gx gwm ATTORNEY.

R E P D. o H c TRIGGERING CIRCUIT 92 0%. SOURCE FIG. 9.

United States Patent 3,134,441 APPARATUS FOR DRILL STEM TESTING Adelhertiiarry and Vfnitman D. Maurice, Houston, Tex assignors, by mesneassignments, to Jersey Production Research Company, Tulsa, 01:121., acorporation of Delaware Original application May 9, 1960, Ser. No.27,730, now Patent No. 3,107,729. Divided and this application May 21,1962, Ser. No. 196,088

6 Claims. (Cl. 66-437) This invention relates to apparatus fordetermining the nature of subsurface geological strata, and moreparticularly to apparatus for use in connection with the sampling ofearth formation fluids.

This application is a division of US. application Serial No. 27,730,entitled Apparatus for Drill Stem Testing, filed May 9, 1960, byAdelbert Barry and Whitman D. Mounce, now Patent No. 3,107,729.

In connection with the drilling of boreholes in the earth for thepurpose of exploiting petroleum deposits therein, often it is desirableto obtain samples of fluids existing in particular formations of theearth through which dril ing operations are progressing. In the interestof econonly, it is particularly desirable to achieve this end withoutwithdrawing the drill stem from the well for the attachment of testingtools as is the present practice. T 0 this end it is necessary to sealoff the lower part of the borehole by means of a well packer. Whileformation fluids often will flow to the earths surface through the drillpipe, more often it is necessary to pump drilling mud out of the lowerportion of the borehole until a relatively pure sample of t e formationfluid can be obtained. Various devices for this purpose have beendevised in the part. Particularly satisfactory drill stem testingapparatus is described in US. Patent No. 2,813,587-W. D. Mounce and inU.S. patent application Serial No. 656,341 for Drill Stem TestingDevice, filed May 1, 1957 by Adelbert Barry and W. D. Mounce, now PatentNo. 3,059,695.

in the construction of drill stem testing apparatus, it is particularlydesirable to isolate the component parts thereof from drilling fluids tobe pumped down the bore of the drill stern, insofar as such ispracticable. The reason for this is that drilling fluids are extremelyabrasive so that component parts of the drill stem testing apparatusthat are in the flow stream of the drilling fluid can be eroded away.Furthermore, it has been found that sand and other constituents of thedrilling fluid have a tendency to pack under moving parts of theapparatus so as to impede their operation.

Another desirable attribute of a drill stern testing apparatus is thatit should not require an electrical cable traversing the bore of thedrill pipe during testing operations for the purpose of actuating thecomponent parts of the drill stern testing apparatus or for conveyinginformation to the earths surface. Manifestly, the electrical leads aresubject to damage. Necessary electrical components of the drill sterntesting apparatus should be entirely selfcontained insofar as such ispossible. It is desirable that such apparatus be suspended in the Wellbore by the conventional swab line on the well.

A still further desirable attribute of drill stem testing apparatus isthat the well packer associated therewith should be held tightly againstthe drill stem during drilling operations to allow unimpeded passage ofdrilling fluids by the packer, and should be adapted to be readilypressed against the sides of the borehole when drilling operations haveceased preparatory to a testing operation. This is necessary in order tominimize damage to the relatively soft borehole seahng parts of thepacker.

The objects and features of the invention will become more apparent uponconsideration of the following de- 3,134,441 Patented May 26, 1964scription thereof when taken in connection with the accompanyingdrawings, wherein:

FIGS. 1 and l-A taken together show a vertical crosssectional View,partially in elevation, of a portion of a drill ng string incorporatingdrill stern testing apparatus in accordance with the teachings of thepresent invention. The apparatus is shown in its nonactuated, orwhiledrilling, position;

FIGS. 2 and 2-A taken in elevation, of the apparatus shown in FIGS. 1and 1-A showing the apparatus in its actuated position for taking asample with actuating and swabbing apparatus in position in the drillingstring;

FIG. 3 is an enlarged vertical sectional view, partially in elevation,of a portion of the go-devil actuating apparatus shown in FIG. 2;

FIGS 4, 4-A, 4-H, and 4-C are vertical sectional views, partially inelevation, of the drill stem swabbing and sample-retrieving apparatusillustrated in FIGS. 2 and 2-A;

FIG. 5 is a fragmentary vertical cross-sectional View, partially inelevation, of portions of the sample-retrieving and go-devil apparatusesshown in FIGS. 2 and 2-A in the sample-taking position;

PEG. 6 is an enlarged vertical cross-sectional view, partially inelevation, of the well packer actuating apparatus of FIGS. 1 and 2. Theapparatus is shown in its nonactuated position;

FIG. 7 is an enlarged vertical cross-sectional View, partially inelevation, similar to FIG. 6 showing the apparatus in its actuatedposition;

FIG. 8 is a horizontal cross-sectional View taken along section 8-8 ofFIG. 6; and

FIG. 9 is a schematic electrical diagram of the electrical portion ofthe triggering apparatus of FIG. 4-A.

With reference now to the drawings, and in particular to FIGS. 1, lA, 2,and 2-A, there is shown a borehole 1 which has been drilled intosubsurface formations. The drill stem 2, in addition to pipe sectionsnot shown, includes the pipe sections designated by the referencenumerals 3, 4, 5, 10, 61, 65, and 74. A drill bit 76 is connected to thelower end of the drill stem. Drill stern sections 4 and it arerelatively thin walled. Drill stem section 4 is the outer member andelastic pipe 6 is the inner member of a section defining a portion ofspace or recess So that acts as a reservoir for hydraulic actuatingfluid for the drill stem testing apparatus to be described. Elastic pipe6 is fastened to collar 8 by annular clamps 6a. Drill stem section it isthe outer member and nonmagnetic pipe section 16 is the inner memberdefining the remainder of the recess or space that acts as thereservoir, and additionally within which is housed certain of the drillstem testing apparatus along with the actuating fluid. The two recessesare interconnected by passageways 14 in the coupling collar 3interconnecting the two sections. Elastic pipe 6 may be formed ofneoprene or other rubber-like deformable material. The elastic pipe issecured at one end to coupling collar 8 by an annular clamp 6a and atthe other end to coupling collar 5 by conventional locking means such asa retainer sleeve 5a.

Packer 66 is aihxed to drill stem section 65 by means of a fixed collarmember 64. The packer may be similar in construction to the packerdescribed in Patent No. 2,828,823 and may include a multiplicity ofcables, or a braid, securely anchored at one end in member 64, and atthe other end to a slidable sleeve member 70. The packer may be formedof rubber or rubber-like material .aflixed to the reinforcing braid orcables 68 by suitable heat treating means known to the prior art. Thefunction of the slidable sleeve-member 70 will be described below.

The packer actuating fluid contained within the recess enclosed withindrill pipe sections 4 and 10 may flow to the packer 66 by passageway 67,passageway 56, check valves 50 and 52, and a control or slide valve 42.A port 53 in passageway 56 is in fluid communication with check valve52. The function of slide valve 42 and check valves 50 and 52 is topermit fluid flow from the reservoir to the packer in one position ofthe slide valve, and to permit fluid flow from the packer to thereservoir in the other position of the slide, valve. The construction ofthe slide valve and the check valves and the interrelation therebetweenwill be described below.

The function of go-devil 63 shown in FIG. 3 is to prevent the downwardflow of drilling fluid through the bore of the drill pipe whilepermitting upward flow of drilling fluid through the bore. The go-devilalso functions to actuate a member in the sample-retrieving apparatus tobe described below. The go-devil is provided with an elongated spacer71, a tubular body member or mandrel 38, a valve section 29, and anactuating member generally designated 25. A pair of packer cups 41 areaflixed to body member 38 for the purpose of preventing downward flow ofdrilling fluid around the outside of the godevil. The length of thespacer rod '71 is suflicient to place the packer cups '41 betweenelastic pipe section 6 and elastic pipe section 60. The spacer rod bearson the 'stem and has a generally hemispherical valve member 174 at thelower end thereof that normally fits into the upper opening of the bore179. Thus, fluids passing upwardly through the bore 179 will lift thehemispherical member and will pass out of the go-devil through ports 37into the bore of the drill stem. The pressure of drilling fluid abovethe packer cups 41 will tend to force the hemispherical valve member 174downwardly to efiectively seal the well bore against fluid flowdownwardly therethrough.

. A permanent magnet 39 is affixed to body member 38 for a purpose thatwill become apparent below.

The general arrangement of the component parts of the swabbing andsample-retrieving unit or housing 81 is shown in FIGS. 2 and 2-A. Theunit is suspended from a swab line 82 by means of a coupling head 83.Below the coupling head are a latch section 84, a solenoid section 86, apressure switch 88, a battery housing section 90, a triggering circuitsection 92 including a pair of spaced-apart electrodes 94, a swab cupsection 96, and a sample tube 98 along with the actuating apparatustherefor, and an overshot 7 for the purpose of latching onto theretrieving head 170 of member 25 of g'o-devil 63.

The details of construction of the swabbing and sample-retrieving unit81 are best shown in FIGS. 4, 4-A, 4-B, and 4-C. As is shown, thecoupling head 83 is connected to an elongated mandrel 100 whichterminates 'in a latching head 102 adapted to receive the opposedmembers 104 and 106 of pivoted latch 108. A 'cavity is provided in thehousing in latch section 84 to accommo- "date the latch section andmandrel 100. A locking dog 83a is provided for the purpose of locking tothe lower reduced section 101 of mandrel 100 after the mandrel isreleased from the grip of latch 108. The opposed latching members 106and '104 of latch 108 are held in position against the force exerted bya cross spring 112 when the latch trip is in the position shown inFIG.'4by stop member 118a on connecting bar 118. The cross spring fits intoslots 114 out in the opposed latching members 104 andf106. The lowerends of members 104 and 106 are respectively pivotally connected to theends of linkage members '104a 1and 106a. The upper end of connecting bar118 is connected to the other ends of linkage members 104a and v106a.Sufficient clearance exists between members 104 and 106 and the latchinghead 102 so 4 that the upper ends of opposed latch members 104 an 106can swing toward each other when the lower ends are forced apart byconnecting bar 118 as it moves upwandly. When the connecting bar 118 ismoved upwardly by plunger 124 responsive to energization of coil 126,the cross spring :112 opens the latching members 106 and 104 to releasethe mandrel 100. Mandrel 100 is telescopically arranged with respect tothe housing section 99 and is shown in its most telescoped position(i.e.,

the position at which mandrel 100 extends as far as possible intohousing section 99). When released by the latch, the entire housing willdrop. Locking dog 83a will pop inwardly under the impetusof spring tohold the mandrel in its least telescoped position.

The pressureswitch 88, battery 90, triggering circuit section 92, andelectrodes 94 function to energize solenoid 126 to trip the latch 108and release mandrel 100 when the mud in the borehole surrounding theapparatus is of a predetermined resistivity. The schematic electricaldiagram of FIG. 9 illustrates the electrical interconnection of theapparatus. The DC. source 200, which may be a battery, is housed in thebattery section 90. The output terminals 204 and 206 of the source areconnected to a chopper or inverter 202 and also are connected to anamplifier 228 by means of leads 208 and 210 to provide. operating biasfor the amplifier. Chopper or inverter 202 may be a transistorizeddevice such as is illustrated in Patent No. 2,849,614--G. H. Royer eta1. Mechanical inverting devices also may be used. The alternatingoutput signal of chopper 202 is applied to input terminals 220, and 222of a bridge circuit including resistors 212, 214, and 216, and .theresistance across electrodes 94. The resistance of resistors 212, 214,and 216 is adjusted so that a signal of predetermined amplitude willappear across output terminals 224 and 226 when the resistivity'of themud or fluid between electrodes 94 is of a predetermined value. Thealternating output signal appearing across terminals 224 and 226 isamplified by amplifier 228 and applied to solenoid 126 by means of leads230. The solenoid 126 is adapted to exert a pull on plunger 124 so as totripthe latch circuit when the fluid resistivity between electrodes 94is of a predetermined value. The fluid appearing between electrodes 94enters the chamber within which the electrodes are housed by means ofelongated ports 93 in the housing. Pressure switch 88 may be connectedbetween D.C. source 200 and terminal 204. The pressure switch closeswhen the apparatus has reached a desired depth in the borehole topositively prevent premature energization of solenoid 126.

The sampling tube section of the apparatus is illustrated in detail inFIGS.- 4-B and 4-0.

The swab cups 96 are affixed to a reduced section of the housing. Thediameter of the swab cups is such as to contact the sides of the drillstem so that fluid above the swab cups will be. pulled upwardly as theswab line is lifted. When the apparatus is dropped, fluid will flowthrough ports 136, through the drilled passageway 134 within the reducedsection to which the swab cups are connected, will lift the ball checktraveling valve 132, and will pass outwardly through ports 133; thus,fluid will be pumped up the valve stem by reciprocating the apparatus inthe drill stem. The sample chamber is provided within housing section 98Y of the apparatus. A check valve 142 is provided at the 7 inlet. port144 to the sample chamber 140 for the purpose of permitting fluid entryinto and preventing fluid exit from the sample chamber. A screw plug140a and check valve 140]; in passageway'140c at the upper end ofchamber140 are for the purpose of providing access to chamber 140 to removefluid therein. After sample tube 98 is unscrewed from the other portionsof unit 81, screw plug 140a is removed and check valve 14% (whichopposes fluid egress from the chamber 149) is stabbed open so that fluidwill flow from chamher 149.

Fluid entry into passageway 144 is controlled by a valve including apiston member slidable within chamber 146. Port 148 provides fluid entryinto the chamber 146. A spring 54 in the enlarged oil filled chamber 156functions to hold the valve piston 15% away from the position whereatdrilled passageway 152 therein will provide fluid communication betweenport M8 and passageway 144. A threaded annular fitting 159 interconnectsthe lower end of piston 15d with an actuating shaft 163 therefor. Theclearance between fitting 159 and the sides of chamber 156 is onlyenough to permit slow movement thereof in an upward direction.Passageways 158 and 164 are drilled in the piston and a check valvearrangement including ball 162 an spring 1&8 is provided to permit thepiston to move quickly downward under the impetus of spring 154. Anovershot arrangement 15:: is provided at the lower end of the housing tolatch onto the retrieving head of godevil 63 when the retrieving head17%) shoves the actuating shaft 168 a sumcient distance upward. In FIG.5 the overshot is shown latched to the retrieving head 17!). In thisposition the valve stem will be as shown in FIG. 5 so that fluid flowwill be permitted through port 143, passageways 152 and 144, throughcheck valve 142, into the sample chamber 149.

The valving arrangement for controlling the flow of actuating fluid fromreservoir 3a to the packer, and from the packer to the reservoir, isshown in FIGS. 6, 7, and 8. In FIG. 7 the apparatus is shown in theposition which it will assume when the drill stem is making hole andwhen it is desired to flow fluid from the packer to the reservoir. InFIG. 6 the apparatus is shown in the position whereat fluid underpressure will flow from the reservoir to the packer.

The control valve apparatus 4-2 comprises a valve housing 4241 having a.passageway 183 drilled therein adapted to receive a valve stem 181?. Thevalve housing is provided with a port 186 opening into the reservoir 3a,a port 183 connected to a check valve by connection 183a and line 13317for permitting fluid flow from the reservoir to the packer, and anotherport 1&4 connected to a check valve 52 by connection 184a and line 1841)for permitting fluid flow from the packer to the reservoir. The valvestem 18) has a multiplicity of longitudinal slots cut thereinsubstantially equal in length to the longitudinal distance along thevalve housing between ports 184 and 186 and between ports 186 and 188.Annular slots 135 and 157 are respectively hydraulically connected toports 13 iand 188 so that :hen the valve stem 18% is in the positionshown in FIG. 6, port 186 is hydraulically connected to port 183, and sothat when the valve stem is in the position shown in FIG. 7, port 186will be hydraulically interconnected with port 184.

A coil spring 1% is provided in a well within a fitting 191 at thebottom of the valve housing. Spring 1% bears against the bottom of valvestem 13 so as to urge the valve stem in an upward direction. A secondspring 28 connected to a shoulder 44 at the top of the valve stemhousing 24 bears against actuating shaft 26 for substantially the samepurpose. Shoulder 46 is ported and drilled so that the upper end ofchamher 183 is in hydraulic communication with the fluid reservoiraround the valve housing through ports 4 3a.

A port 194 is provided fitting 191 so that the lower end of the chamber183 is in hydraulic communication with a passa eway 58, which in turn ishydraulically connected to a recess 62 in valve stem section 61 (seeFIGS. 1 and 2). The ecess 62 surrounds elastic pipe section so that whenthe piston 18% is in the position shown in FIG. 7, the elastic sleevewill bulge slightly into the recess 62 as shown in FIG. 2.

Returning to FIGS. 6 and 7, it is seen that at the projecting annularflanges upper end of the actuating shaft 26 there is provided a pivotedmember including a pivoted arm 23 pivotally afiixed to a slotted ballmember 27. A slot 27a is cut in the ball member so that the actuatingshaft 26 will assume the position shown in FIG. 7 when the arm 23 isrotated from the position shown in FIG. 6 to the position shown in FIG.7. Spring 22 is provided for urging the arm to the position shown inFIG. 6. The arm is pivotally supported within the drill stem by asuitable support means 2i A clevis member 24 is connected to one end ofthe pivoted arm 23 and partially surrounds the nonmagnetic pipe member16. A clevis actuating member 19a is aflixed to the inner pipe member 15so as to drive the clevis 24 from the position shown in FIG. 6 to theposition shown in FIG. 7 when a magnet 19 slidably mounted on the pipemember 16 strikes the lower end of the clevis actuating member 19a. Themagnet 19 is supported by an annular stop member 21 and is free to slidebetween the clevis actuating member 19a and the annular stop member 21.

Turning again to FlGS. 1 and 2, it is seen that the sliding lower anchormember 7t? for the flexible packer 65 comprises a tubular outer section211 1 having inwardly 263 and 285 at the upper and lower ends thereofrespectively. The tubular outer section 2%1 slidingly engages an annularflange 297 on drill stem section 65. Thus there is formed between thedrill stem section 653' and the member 291 first and econd cavities 2tand 211, the volume of which increases and decreases as the member 231slides up and down on flange 2&7. Cavity 299 is in fluid communicationwith the borehole annulus through at least one port 72 which at alltimes is above flange 287. Cavity 211 is in fluid cornmunication withthe drill stem bore through at least one port 213 below flange 2 57. Thebraid or cables of the packer are anchored to the upper end of member70.

When hydraulic pressure is applied to the drill stem and there is noobstruction therein so that fluid circulation is possible, the pressuredrop across the bit forces member 71 down since the pressure drop isexerted across member 79 through port 213. However, when the godevil 63prevents fluid circulation, or when there is no hydraulic pressureapplied to the drill stem, the member '73 is free to move up whenhydraulic pressure is exerted on the interior of packer member 66through passageway 67.

During drilling operations the apparatus will assume the position shownin FIG. 1. The packer will be held against the drill stem by virtue ofthe differential pressure across the drill bit exerted on the slidingsleeve member 79. When it is desired to conduct a drill stem test,godevil 63 is dropped into the bore of the drill stem. Spacer bar 71will space the packer cups 41 between the elastic pipe sections 6 and6?. Heavy hydraulic pressure is then exerted down the bore of the drillstern. By virtue of the action of the elastic pipe 6, the hydraulicforce within the drill stem will be exerted on the valve stem 18% toforce the valve stem into the position shown in FIG. 6. Pivoted arm 23will rotate due to the pull exerted by spring 22 so that the sphericalmember 27 will hold the valve stem 1811 in the position shown in FIG. 6.Fluid may then flow through port 186, through slots 182, through port 138, check valve 56, passageways 56 and 67 and will be exerted againstthe inner side of the packer. Sleeve member 719 will be permitted toslide upwardly inasmuch as the e is now no differential pressureexisting across the drill bit. Hydraulic pressure may now be released.By virtue of the latching action. of the spherical member 27 and thecheck valve 51), the packer will stay in its inflated position shown inFIG. 2.

The swabbing and sample retrieving member 81 may now be lowered into thebore of the drill stem until the swab cups are adjacent drill stemsection 3. This may be done by lowering member 31 until retrieving head17%) engages member 1 68. The dashpot action of fitting 159 7 willprevent the stem 159 from moving up rapidly to prematurely open thesampling chamber. Member 81 maybe lifted a short distance in drill sternsection 3 and spring 154 will quickly force member 168 back to itsoriginal position (ball 162 will unseat to permit fluid flow throughpassageway 164-). The swabbing unit may then be reciprocated in drillstem section 3 without contacting retrieving head 170 to pump fluid outof the earth formation, through ports 59, through passageway 179,through ports 37, up the drill stem bore between the godevil and theswabbing unit, and through the swaboing unit into the, portion of thedrill stem bore immediately above cups 96. As the fluid around theelectrodes 94 changes from drilling fluid to earth formation fluid, theresistivity thereof will change. When the resistivity has reached apredetermined value, the electrical triggering circuit will energizesolenoid 126 to trip the latch 19S and release mandrel 100. The entireswabbing and sampling apparatus will suddenly drop, which will produce asudden jerk on the swab line.

I Additionally, during the swabbing operations, the swabbing member 81is periodically lowered to rest on top of the go-devil 63. This gives adepth reference which may be marked on the swab line at the wellhead.The swab line weight is indicated at the wellhead. (When the swabbingmember 81 comes to rest on the go-de'vil 63, ,a weight indicator fallsoff.) Bottom reference may be made as often as desired. Short movementsof valve stem 150 are not additive due to the return feature of thecheck valve arrangement (ball 162 and spring 169). Therefore, inaddition to a jerk on the swab line (which may be missed by theoperating personnel), a positive indication that the mandrel 100 hasbeen released by a detected change in the resistivity of the well fluidis observable at the wellhead byran apparent increase in the length ofthe swab line upon a bottom reference check. In other words, whenmandrel 100 has been released, the mark on the wire line will be at adistance from the well head equal to the length of the mandrel whenmember 81 is again resting go-devil '63. This increase in length of theswab line will be equal to the length of the mandrel 100. Upon thisindication at the surface, a sample may then be obtained by allowing theswab unit 81 to rest upon the go-devil 63 [for a long enough period toascertain movement of the valve stem 150 for its full stroke which willopen the sample chamber and allow latching onto the go-devil '63. Whenthe retrieving head 170 is engaged by the overshot 166 (see FIG. 5), thevalve stem 150 ismoved to the position as shown, and formation fluidwill flow into the sample chamber which is at atmospheric pressure untilthe pressure between the sample chamber and the well bore therearounddrops to a value suflicient to close check valve 142 and retain theformation fluid sample. Both the swabbing and sample-retrieving unit 81and the go-devil 63 may then be retrieved from the well bore. As themagnet 39 passes by the magnet 19, the mutual attraction therebetweenwill cause magnet 19 to be lifted until clevis 24 is stricken by member19a and pivoted arm 23 will be rotated, releasing the valve stem 180 sothat it is free to assume the position shown in FIG. 7. When thego-devil 63 has been removed from the well bore, drilling fluid pressurewill force packer anchor member '70 down to the position shown in FIG.1, thereby forcing fluid up the passageways 67 and 56 through checkvalve 52, port 184, slots 182, and port 186 into the fluid reservoir.After a s-ufficient time to allow the packer to be deflated, drillingoperations may recommence.

The invention is not to be restricted to the specific structuraldetails, arrangement of parts, or circuit con- The objects and featuresof the invention having been completely described, what we wish to claimis:

1. Apparatus for hydraulically inflating an inflatable packer aflixed tothe exterior of a drill stem responsive to exertion of fluid pressure inthe bore of the drill stern, comprising:

a first drill stem section having an outer tubular member and an innertubular member defining a space therebetween; a

said inner tubular member including an elastic tubular sectiondeformable by fluid pressure within the bore of the drill stem, and anonmagnetic tubular section;

a substantially incompressible liquid in said space;

a control valve in said space comprising a valve stem,

a valve housing for said valve stem having first, second, and thirdports, said first port being in hydraulic communication with said space,said valve stem including means to hydraulically interconnect said firstand second ports when said stem is in a first postion thereof, and tohydraulically interconnect said first and third ports when said stem isin a second position thereof;

means in said valve housing urging said valve stem toward said firstposition thereof;

means including first check valve means hydraulically interconnectingsaid third port to said packer, adapted to allow fluid flow only fromsaid third port to said packer to inflate said packer;

means including second check valve means hydraulically interconnectingsaid packer to said second port to permit fluid flow only from saidpacker to said second port;

a second drill stem section below said first drill stern section,including a recess therein and a second elastic tubular section betweensaid second recess and the bore of the drill stem;

a passageway providing hydraulic communication between said secondrecess and said valve housing to permit free movement of said valvestem;

a valve stem latching mechanism including a pivoted arm bearing againstthe valve stem and further including means for latching said valve stemin said second position thereof when said valve stem moves to its secondposition, means pivotally supporting said pivoted arm in said space,spring means connected to the pivoted arm and to the drill stem adaptedto urge the pivoted arm against the valve stem and to rotate the arm toits latching position responsive to movement of the valve stem, and aclevis of magnetizable material afiixed to said pivoted arm andpartially surrounding the bore of the drill stem adapted to rotate thearm away from'its latching position against the force of said springmeans responsive to movement of a magnet up the drill stern bore torelease said valve stem and permit said valve stem to move to its firstposition; and

a go-devil insertable into said valve stem for preventing fluid flowdown said drill stem, said go-devil including a mandrel, cup packermeans on the mandrel for providing a fluid seal between the mandrel andthe Walls of the drill stem bore, andspacer means afiixed to the mandrelfor spacing the cup packer means from the bottom of the drill stem to alevel in the drill stem between said first and second elastic tubularsections. 7

2. Apparatus for hydraulically inflating a packer aiflxed to theexterior of a drill stem responsive to insertion of means for preventingfluid flow down the drill stem at a given level in the drill stern, andexertion of fluid pressure in the bore of the drill stem, comprising:

a first drill stem section having an outer tubular member and an innertubular member defining a space therebetween;

said inner member including an elastic tubular section above said givenlevel in the drill stem deformable 9 by fluid pressure within the drillstem, and'a non magnetic tubular section;

a substantially incompressible liquid in said space;

a control valve in said spacecomprising a valve stem,

a valve housing for said valve stem having first, second, and thirdports, said first port being in hydraulic communication with said space,said valve stem including means to hydraulically interconnect said firstand second ports when said stem is in a first position thereof, and tohydraulically interconnect said first and third ports when said stem isin a second position thereof;

means in said valve housing urging said valve stem toward said firstposition thereof;

means including first check valve means hydraulcially interconnectingsaid third port to said packer, adapted to allow fluid flow only fromsaid third port to said packer to inflate said packer;

means including second check valve means hydraulically interconnectingsaid packer to said second port to permit fluid flow only from saidpacker to said second port;

a second drill stem section below said first drill stem section andbelow said given level, including a recess therein and a second elastictubular section between said second recess and the bore of the drillstem;

a passageway providing hydraulic communication between said secondrecess in said valve housing to permit free movement of said valve stem;and

a valve stem latching mechanism including a pivoted arm bearing againstthe valve stem and further including means for latching said valve stemin said second position thereof when said valve stem moves to its secondposition, means pivotally supporting said pivoted arm in said space,spring means connected to the pivoted arm and to the drill stem adaptedto urge the pivoted arm against the valve stem and to rotate the arm toits latching position responsive to movement of the valve stem, and aclevis of magnetizable material affixed to said pivoted arm andpartially surrounding the bore of the drill stem adapted to rotate thearm away from its latching position against the force of said springmeans responsive to movement of a magnet up the drill stem bore torelease said valve stem and permit said valve stem to move to its firstposition.

3. Apparatus for hydraulically inflating a packer aflixed to theexterior of a drill stem responsive to insertion of means for preventingfluid flow down the drill stem at a given level in the drill stem, andexertion of fluid pressure in the bore of the drill stem, comprising:

a first drill stem section having an outer tubular member and an innertubular member defining a space therebetween;

said inner member including an elastic tubular section above said givenlevel in the drill stem deformable by fluid pressure within the drillstem, and a nonmagnetic tubular section;

a substantially incompressible liquid in said space;

a control valve in said space comprising a valve stem, a valve housingfor said valve stem having first, second, and third ports, said firstport being in hydraulic communication with said space, said valve stemincluding means to hydraulically interconnect said first and secondports when said stem is in a first position thereof, and tohydraulically interconnect said first and third ports when said stem isin a second position thereof;

means in said valve housing urging said valve stem toward said firstposition thereof;

means including first check valve means hydraulically interconnectingsaid third port to said packer, adapted to allow fluid flow only fromsaid third port to said packer to inflate said packer;

means including second check valve means hydraulical- 1y interconnectingsaid packer to said second port to permit fluid flow only from saidpacker to said second port;

means in said drill stem associated with said control valve to providehydraulic relief to the drill stem bore below said given level for saidvalve stem; and

a valve stem latching mechanism including a pivoted arm bearing againstthe valve stem, means for latching said valve stem in said secondposition thereof when said valve stem moves to its second position,means pivotally supporting said pivoted arm in said space, spring meansconnected to the pivoted arm and to the drill stem adapted to urge thepivoted arm against the valve stem and to rotate the arm to its latchingposition responsive to movement of the valve stem, and a clevis ofmagnetizable material affixed to said pivoted arm and partiallysurrounding the bore of the drill stem adapted to rotate the arm awayfrom its latching position against the force of said spring meansresponsive to movement of a magnet up the drill stem bore to releasesaid valve stem and permit said valve stem to move to its firstposition.

4. In a drill stern testing apparatus wherein an inflatable packeraffixed to the exterior of a drill stem is hydraulically inflated byfluid from a fluid reservoir located in a recess between the bore of thedrill stem and the outer surface of the drill stem, wherein fluidpressure within the bore is exerted on the fluid in the reservoir, andwherein the reservoir and the packer are interconnected by a controlvalve in the recess having a movable, valve stem movable within a valvehousing between a first position whereat fluid flow is permitted onlyfrom the packer to the reservoir and a second position whereat fluidflow is permitted only from the reservior to the packer, the valve stembeing movable from the first position to the second position responsiveto fluid pressure exerted thereon from the bore of the drill stem, theimprovement comprising:

a valve latching mechanism operatively associated with said valve stemto lock the valve stem in the second position thereof, said valvelatching mcehanism in cluding a pivoted arm bearing against the valvestem and having a recess adapted to lock the valve stem in its secondposition, spring means pivotally supporting the arm in the recess, meansconnected to the pivoted arm and to the drill stem adapted to urge thearm against the valve stem and to rotate the arm responsive to movementof the valve stem, and a clevis of magnetizable material aflixed to thearm and partially surrounding the bore of the drill stem adapted torotate the arm against the force of the spring responsive to movement ofa magnet therepast up the drill stem bore.

5. In a drill stem testing apparatus wherein an inflatable packeraflixed to the exterior of a drill stem is hydraulically inflated byfluid from a fluid reservoir located in a recess between the bore of thedrill stem and the outer surface of the drill stem, wherein fluidpressure within the bore is exerted on the fluid in the reservoir, andwherein the reservoir and the packer are interconnected by a con trolvalve in the recess having a movable valve stem movable within a valvehousing between a first position where at fluid flow is permitted onlyfrom the packer to the reservoir and a second position whereat fluidflow is permitted only from the reservoir to the packer, the valve stembeing movable from the first position to the second position responsiveto fluid pressure exerted thereon from the bore of the drill stem, theimprovement comprising:

a valve latching mechanism operatively associated with the valve stem tolock the valve stem in the second position thereof, including a pivotedarm bearing against the valve stem and formed to lock the valve stem inits second position;

means pivotally supporting the arm in the recess;

, spring means connected to the pivoted arm and to the drill stemadapted to urge the arm against the valve stem and to rotate the armresponsive to movement of the valve stem; and V a magnetizable member'aflixed to said arm and arranged with respect to the bore of the drillstem so as to rotate the arm against the force of the spring meansresponsive to movement of a magnet therepast up the drill stem bore.

j 6. In a drill stem testing apparatus wherein an inflatable packeraffixed to the exterior of a drill stem is hydraulically inflated byfluid from a fluid reservoir located in a recess between the bore of thedrill stem and the outer surface of the drill stem, wherein fluidpressure within the bore is exerted on the fluidin the reservoir, and

wherein the reservoir and the packer are interconnected is permittedonly from the reservoir to the packer, the valve stem being movable fromthe first position to the second position responsive to fluid pressureexerted thereon from the bore of the drill stem, the improvementcomprising:

' a valve latching mechanism operatively associated with i the valvestem to lock the valve stem in the second 7 position thereof, includingan arm pivotally supported in the recess so as to bear against the valvestem to rotate responsive to movement of the valve stem; spring meansconnected to the pivoted arm and to the drill stern adapted to urge thearm against the valve stem and to rotate the arm responsive to movementof the valve stem; and a magnetizable member aifixed to said arm andarranged with respect to the bore of the drill stem so as to roate thearm against the force of the spring means responsive to movement of amagnet therepast up the drill stern bore.

References Cited in the file of this patent UNITED STATES PATENTS2,742,968 Hildebrandt Apr. 24, 1956 2,813,587 Mounce Nov. 19, 19572,828,823 Mounce Apr. 1, 1958 2,978,046 True Apr. 4, 1961 3,032,116Barry May 1, 1962 3,059,695 Barry et a1 Oct.23, 1962

1. APPARATUS FOR HYDRAULICALLY INFLATING AN INFLATABLE PACKER AFFIXED TOTHE EXTERIOR OF A DRILL STEM RESPONSIVE TO EXERTION OF FLUID PRESSURE INTHE BORE OF THE DRILL STEM, COMPRISING: A FIRST DRILL STEM SECTIONHAVING AN OUTER TUBULAR MEMBER AND AN INNER TUBULAR MEMBER DEFINING ASPACE THEREBETWEEN; SAID INNER TUBULAR MEMBER INCLUDING AN ELASTICTUBULAR SECTION DEFORMABLE BY FLUID PRESSURE WITHIN THE BORE OF THEDRILL STEM, AND A NONMAGNETIC TUBULAR SECTION; A SUBSTANTIALLYINCOMPRESSIBLE LIQUID IN SAID SPACE; A CONTROL VALVE IN SAID SPACECOMPRISING A VALVE STEM, A VALVE HOUSING FOR SAID VALVE STEM HAVINGFIRST, SECOND, AND THIRD PORTS, SAID FIRST PORT BEING IN HYDRAULICCOMMUNICATION WITH SAID SPACE, SAID VALVE STEM INCLUDING MEANS TOHYDRAULICALLY INTERCONNECT SAID FIRST AND SECOND PORTS WHEN SAID STEM ISIN A FIRST POSITION THEREOF, AND TO HYDRAULICALLY INTERCONNECT SAIDFIRST AND THIRD PORTS WHEN SAID STEM IS IN A SECOND POSITION THEREOF;MEANS IN SAID VALVE HOUSING URGING SAID VALVE STEM TOWARD SAID FIRSTPOSITION THEREOF; MEANS INCLUDING FIRST CHECK VALVE MEANS HYDRAULICALLYINTERCONNECTING SAID THIRD PORT TO SAID PACKER, ADAPTED TO ALLOW FLUIDFLOW ONLY FROM SAID THIRD PORT TO SAID PACKER TO INFLATE SAID PACKER;